• 한국항해학회지
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• 제5권2호
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• pp.59-88
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• 1981

Many studies have been done in the field of fuzzy logic theory, but it's application is not so much, and particularly, there isn't any application to the ship's steering system, until now. This paper is to survey the effect of application of fuzzy logic control to the ship's steering system. The controller is made up of a set of Linguistic Control Rules which are conditional linguistic statements connecting the inputs and the output, and take the inputs derived from the errors, that is, deviation angle and it's angular velocity. These two variables together give information about the state of the steering system, and the Linguistic Control Rules are implemented on the digital computer. The characteristics of this system were investigated through the computer simulation and satisfactory results compared with that of the conventional PD controller were obtained.

• 제어로봇시스템학회논문지
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• 제22권8호
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• pp.671-677
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• 2016

A Controller Area Network (CAN) is a serial communication protocol that is highly reliable and efficient in many aspects, such as wiring cost and space, system flexibility, and network maintenance. Therefore, it is chosen for the communication protocol between a single chip controller based on Field Programmable Gate Array (FPGA) and peripheral devices. In this paper, the design and implementation of CAN IP, which is written in VHSIC Hardware Description Language (VHDL), is presented. The implemented CAN IP is based on the CAN 2.0A specification. The CAN IP consists of three processes: clock generator, bit timing, and bit streaming. The clock generator process generates a time quantum clock. The bit timing process does synchronization, receives bits from the Rx port, and transmits bits to the Tx port. The bit streaming process generates a bit stream, which is made from a message received from a micro controller subsystem, receives a bit stream from the bit timing process, and handles errors depending on the state of the CAN node and CAN message fields. The implemented CAN IP is synthesized and downloaded into SmartFusion FPGA. Simulations using ModelSim and chip test results show that the implemented CAN IP conforms to the CAN 2.0A specification.

• Journal of Contemporary Eastern Asia
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• 제20권2호
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• pp.210-236
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• 2021

China's Belt and Road Initiative infrastructure connectivity and other projects are presented in much of the discourse as a grand strategy to trap developing nations in debt, to exert asymmetric power and construct a new world economic order. The asymmetric relationship between China and Myanmar might therefore be expected to generate a range of political risks for stakeholders. Myanmar itself presents a "perfect storm" of problems, with dysfunctional governance, civil conflict, under-development and growing economic dependence on China. The Kyaukphyu port project and associated Special Economic Zone in Myanmar's troubled Rakhine state is investigated as a case study of risks on the Belt and Road. While worst case fears China might seize military control of the port appear unlikely, at least in current conditions, empirical observation indicates the complexity on the ground generates an array of other risks - as well as opportunities, should conditions allow. Further, despite challenges and constrained capacity, Myanmar governments have demonstrated agency, including by re-negotiating control and costs of the Kyaukphyu project. The case underlines that conditions are more complicated than simply China's asymmetric power. A sceptical approach is taken to normative discourses in order to build inductive understanding of how stakeholders and local experts perceive dynamics underway. A political risk approach is deployed to develop a framework to identify, analyse and assess risks for actors in relation to the Kyaukphyu project. The research findings are presented on an interim basis, given current constraints on field interviews due to the current crisis.

• 정보처리학회논문지C
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• 제9C권1호
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• pp.45-54
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• 2002

본 논문에서는 차세대 인터넷으로 진화할 수 있는 새로운 핵심 기술로 평가받고 있는 MPLS(Multiprotocol Label Switching) 네트워크에서 QoS를 제공하기 위하여 DiffServ(Differentiated Services)를 지원하는 동적 흐름 수락 제어를 제안한다. 제안 모델은 아웃 포트의 전송 가능한 용량을 계산하여 이 용량에 맞게 흐름을 받아들이고 패킷을 전송한다. 또한 QoS 라우팅 테이블을 위한 정보 교환으로 혼잡 지역을 알 수 있는 ingress LSR은 혼잡 지역을 배제한 경로로 패킷을 전송하게 한다 이렇게 함으로써 제안 모델은 DiffServ의 단점으로 인정되는 자원 낭비를 막고 자원을 효율적으로 관리하여 자원의 이용률을 높이고 서비스 받기 위해 네트워크에 진입하는 흐름의 수를 높일 수 있다.

• 한국항해항만학회지
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• 제31권6호
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• pp.515-521
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• 2007

컨테이너 화물의 복합운송시스템 중에서 체화현상은 항만에서 가장 심각하다. 이러한 문제를 해결하기 위해 해상과 육상의 경계선에서 체선체화 문제를 발생시키는 컨테이너 크레인의 직업효율을 향상시키는 방법을 생각할 수 있다. 이를 위해 본 연구에서는 가능한 범위에서 트롤리를 목표지점까지 빠르게 이동시키는 동시에 목표위치에서의 흔들림도 짧은 시간 내에 제어하는 문제를 다루고 있다. 제어 전략으로 설계된 구간에서 최적의 성능과 강인성이 보장되는 LQ 제어와 제약조건에서 최적화가 가능한 실수코딩 유전알고리즘을 결합한다. 컴퓨터 시뮬레이션을 통해 제안한 제어기가 설정한 설계사양을 완벽하게 만족하는 것을 보임으로 그 유효성을 증명한다.

• 한국항해항만학회지
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• 제38권2호
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• pp.135-140
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• 2014

2013년 8월 20일 해사노동협약이 국제적으로 발효되면서 휴식시간의 실제적인 이행 여부를 항만국통제에서 점검하게 되었다. 한일간 셔틀 운항을 하는 선박은 항해시간이 짧고 입항 항구수가 많아 해사노동협약이나 우리나라 선원법에서 정하고 있는 선원휴식시간을 준수하지 못하는 경우가 발생하고 있으며, 이는 선박의 운항에 큰 지장을 초래할 수 있는 사항이 되었다. 이 연구에서는 이러한 선박들에서 휴식시간 규정을 준수할 수 있는 방안을 찾기 위해 항해사들의 당직모델을 여러 가지로 변경하거나 정박당직을 육상직원으로 대체하는 방안 등을 검토하였다. 한일간 셔틀 운항 선박이 휴식시간 규정을 만족하기 위해서는 입항 항구 수의 축소 또는 정박당직의 육상직원 대체와 같은 방안의 복합적인 적용이 필요한 것으로 연구되었다.

• 해양환경안전학회:학술대회논문집
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• 해양환경안전학회 2003년도 춘계학술발표회
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• pp.41-58
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• 2003

A recent trend of global shipping industry adopting Port State Control (PSC) system is recognized as a proficient mechanism in preventing costal traffic accident and protecting marine environment. Disadvantages of Korean shipping companies in PSC inspection are unavoidable as Tokyo MOU imposed priority listed flag to Korea. Having stated above, appropriate research and prompt preparation in compliance with current PSC requirements for the Korean shipping companies have become an immediate need. The objectives of this study are : First, to review in understanding of PSC in overall and foundation of enforcement. Second. to study interaction of international treaties regarding PSC. Third, to compare practical compliance among the countries and to open up a case study on Korean shipping companies in adopting PSC. Last, to suggest direction to the Korean shipping companies the most proficient way in compliance with the current Tokyo MOU requirement. Korean flagged vessels have become prioritized target in PSC inspection as Tokyo MOU imposed priority listed flag to Korea due to high detention rate of its fleet. Disadvantage of a priority listed flag is a burden in its proficient fleet operation. This study suggests solutions to the disadvantages as below. : 1) Change shore management system, and provide continuous & quality education to crew members 2) Form a network in sharing PSC information among the Korean shipping companies 3) Form a centralized function in which government, Korean Shipping register and shipowners can treat problems in a prompt manner.

• 해양환경안전학회지
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• 제9권1호
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• pp.1-15
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• 2003

이 연구의 목적은 첫째, 항만국 통제의 의의 및 시행배경과 이론을 고찰하고, 둘째, 항만국 통제와 관련된 국제협약관계를 고찰하며, 셋째, 항만국 통제에 대한 국제비교와 우리나라 해운기업의 사례를 분석하며, 마지막으로 이러한 분석결과를 토대로 항만국 통제에 대한 우리나라 해운기업의 대응방안을 제시하는데 있다.

• 수산해양교육연구
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• 제29권2호
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• pp.333-342
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• 2017

In this study, we studied and analyzed 3,751 ships regarding detention list of Tokyo MOU from 2013 to 2015 total for 36 months. The Member Authorities of the MOU has 20 committee consists of Korea and Peru joined in 2015. 1,250 ships in a year and 140 ships in a month are granted PSC Action Code-30 corresponding to detention. Averagely, 30,943 ships in a year and 2,579 ships have been received PSC inspection. Additionally, according to this PSC inspection, rate of Detention reaches to 4.04%. When it comes to Korean Flag Ships however, the number of Detention ships of Tokyo MOU has been rather increased from 3 ships in 2013 to 18 ships during 2years. Furthermore, MOU in the all over the world, the number of ships had Detention has largely increased from 5 ships to 9 up-to 19ships. The number of Detention Ships has been reached to 44.8% of 1~2 days period of Detentions, under 3~10 days period of Detentions reaches to 34.7% and over 10 days detention reaches 10.3%, which cause economically enormous loss. Continually, each MOU has been implemented Concentrated Inspection Campaign(CIC) annually. Each MOU including Tokyo MOU implemented "Crew Familiarization for Enclosed Space Entry" for 3 month from september, and During this period, Concentrated Inspection were carried out to 8,429 ships of Tokyo MOU. Accordingly, If ships and owners can get the information of CIC and deliver the information to the ship, then Ships can minimize the rate of Detention by thoroughly preparing for PSC Inspection. In addition, Bulk Carrier and General Cargo ship occupy 50% of rate of Detention and it shows that majority of list among Nature of Deficiencies are identical. Finally, If we can obtain the information of the ships inspected previously, We can reduce the number of detention by preparing for PSC inspection. And this will be able to contribute to shipping industry also.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2006년도 추계학술대회 논문집(제1권)
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• pp.405-413
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• 2006

본 논문에서는 비선형 동적 마찰 성분을 효과적으로 보상하고 적응적으로 제어함으로써 차세대 항만 자동화 이송시스템으로 주목받고 있는 LMTT(linear motor-based transfer technology)의 위치 정밀도를 향상시키는 것을 목적으로 하고 있다. 셔틀카(shuttle car)와 컨테이너들의 다양한 중량과, 이로 인해 발생하는 동적 마찰 특성 파라미터들을 정확하게 추정할 수 있는 관측기를 설계하였다. 적응 backstepping 제어 기법을 적용하여 시스템이 안정하게 제어될 수 있도록 하는 제어기를 설계하였다. 시스템은 변화하는 환경에 대하여 높은 적응성을 가질 수 있어 여러 종류의 부하는 물론 마찰 특성의 변화에도 양호한 제어 특성을 유지할 수 있었다. 제안한 제어시스템의 타당성을 보여주기 위해 축소된 형태의 LMTT 시뮬레이터를 제작하여, 이에 대해 시뮬레이션과 실험만을 수행하여 제안하는 방법의 타당성과 실현성을 입증하고자 하였다.